fix(text area): update code editor constructor

Update the `TextArea.code_editor` convenience constructor to include the
new `read_only` and `max_checkpoints` attributes.

src/textual/widgets/_text_area.py

@@ -462,7 +462,9 @@ def code_editor(
         theme: str = "monokai",
         soft_wrap: bool = False,
         tab_behavior: Literal["focus", "indent"] = "indent",
+        read_only: bool = False,
         show_line_numbers: bool = True,
+        max_checkpoints: int = 50,
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
@@ -491,7 +493,9 @@ def code_editor(
             theme=theme,
             soft_wrap=soft_wrap,
             tab_behavior=tab_behavior,
+            read_only=read_only,
             show_line_numbers=show_line_numbers,
+            max_checkpoints=max_checkpoints,
             name=name,
             id=id,
             classes=classes,